For decades, it was known as the Ghost Station. On Line 1 of the Madrid Metro between Bilbao and Iglesias, alert passengers could spot a dark, abandoned station as the train sped through it.

The Chamberí Station had served riders from October 17, 1919, when King Alfonso XIII inaugurated the Metro system, until May 21, 1966. To accommodate the growing number of passengers, the Metro decided to increase the number of cars in each train, and the station couldn't be expanded, so it was closed.

The Chamberí Station needed lots of cleaning. Over the years, water had seeped in and damaged ceilings and walls. Homeless people had camped in its halls, and their fires had left a layer of soot. Graffiti had added to the damage. The original entrance had disappeared under widened streets, so a new glass and steel circular stairway was built in Chamberí Plaza.

At first, people thronged to the new museum-station to enjoy the time machine that it was meant to be. Crowds have since thinned but by no means stopped. Twenty people passed through at the same time I did on a Sunday early afternoon.

A talkative tour guide, too young to have ever used the station herself but enthused about it, walked our group through the ticket booth, down the hallway and stairs, back and forth on the platform, and then out through the turnstiles, explaining each detail down to the electric light bulbs. Every effort has been made to make restore the station to its 1919 condition, she said, but these days public law requires minimal lighting in museums that is much brighter than the bulbs available back then. She quoted a contemporary newspaper column about the inauguration complaining that the lighting was "gloomy."

The Metro's architect, Antonio Palacios, famous in Madrid's history, did his best to fight the gloom. Shiny white ceramic tiles cover the walls and ceiling, accented with cobalt blue. Some of the colorful original tile advertisements on the walls could be saved, protected by paper billboards slapped over them as time went by. The telephone numbers on them have four digits. Music from the 1920s plays over loudspeakers, and the spaces for ads that could not be saved serve as screens to project other old ads and historic films.

A new glass wall alongside the tracks protects visitors as trains roar through frequently. Old signs and subway maps on the walls tell how much has changed. Originally, the Madrid Metro had 8 stations; now it has 292.

A video in an adjoining little theater recounts the entire history of the subway and how King Alfonso himself led the effort to create the Metro. It initially employed pretty young women in its ticket booths to attract users who just wanted to see the novelty of women at work.

Foreign tourists rarely go to Andén Cero. It's not their ghost, not their past or their grandparents' pasts, and a small antique subway station lacks the allure of the Prado Museum. Everything's in Spanish, anyway.

But I live here. I'd seen the Ghost Station for years, and now I've seen the Metro as it was 90 years ago, odd and quaint, but in its day a giant leap toward a better future, such as it was conceived of back then — for example, one of the advertisements proclaims the modern wonder of a Philips light bulb with the illuminating power of one-half watt.

I've whizzed through there many times and wondered about it: never seen anybody on the platform though. I've also seen the entrance structure, but assumed it was a flashy entrance to an underground car park. Now you've joined them up: I shall visit soon. Thanks.